Re: [PATCH] linux-custom: Speedup build of target specific linux-kbuild package

["Koch, Stefan" <stefan-koch@siemens.com>]

On Tue, 2024-06-04 at 18:18 +0200, Jan Kiszka wrote:
> > On 04.06.24 17:39, Stefan Koch wrote:
> > > > Avoids time expensive QEMU-emulated merging of kernel config
> > > > by using a pregenerated kernel config for target specific
> > > > linux-kbuild
> > > > 
> > 
> > Hmm, it's a bit heavier to install, but we already have the config
> > packaged: in linux-image under /boot/config-*. Or is this not
> > always
> > the
> > case?
Yes, that's right. I'll send an updated patch.
It will copy the config from linux-image while build time is the same
as with separate linux-config package.
> > 
> > Jan
> > 
> > > > Using DEPENDS instead of RDEPENDS ensures creation of
> > > > pregenerated kernel config before build of target specific
> > > > linux-kbuild
> > > > 
> > > > Signed-off-by: Stefan Koch <stefan-koch@siemens.com>
> > > > ---
> > > >  .../linux/files/debian/control.tmpl            |  8 ++++++++
> > > >  .../linux/files/debian/isar/common.tmpl        |  2 ++
> > > >  .../linux/files/debian/isar/configure.tmpl     | 18
> > > > ++++++++++++++----
> > > >  .../linux/files/debian/isar/install.tmpl       | 15
> > > > +++++++++++++++
> > > >  meta/recipes-kernel/linux/linux-custom.inc     | 14 +++++++++-
> > > > ----
> > > >  5 files changed, 48 insertions(+), 9 deletions(-)
> > > > 
> > > > diff --git a/meta/recipes-
> > > > kernel/linux/files/debian/control.tmpl
> > > > b/meta/recipes-kernel/linux/files/debian/control.tmpl
> > > > index e0e932a0..fa2b4e12 100644
> > > > --- a/meta/recipes-kernel/linux/files/debian/control.tmpl
> > > > +++ b/meta/recipes-kernel/linux/files/debian/control.tmpl
> > > > @@ -50,6 +50,14 @@ Description: Linux kernel debugging symbols
> > > > for
> > > > @KR@
> > > >   This package will come in handy if you need to debug the
> > > > kernel.
> > > > It provides
> > > >   all the necessary debug symbols for the kernel and its
> > > > modules.
> > > >  
> > > > +Package: linux-config-${KERNEL_NAME_PROVIDED}
> > > > +Build-Profiles: <kconfig>
> > > > +Architecture: all
> > > > +Depends: ${perl:Depends}, ${shlib:Depends}
> > > > +Description: ${KERNEL_NAME_PROVIDED} Linux kernel config for
> > > > @KR@
> > > > + This package provides the kernel config for @KR@
> > > > + The target specific linux-kbuild package benefits from a
> > > > reduced
> > > > build time.
> > > > +
> > > >  Package: linux-kbuild-${KERNEL_NAME_PROVIDED}
> > > >  Build-Profiles: <kbuild !cross>
> > > >  Architecture: any
> > > > diff --git
> > > > a/meta/recipes-kernel/linux/files/debian/isar/common.tmpl
> > > > b/meta/recipes-kernel/linux/files/debian/isar/common.tmpl
> > > > index 86af70c5..6666c414 100644
> > > > --- a/meta/recipes-kernel/linux/files/debian/isar/common.tmpl
> > > > +++ b/meta/recipes-kernel/linux/files/debian/isar/common.tmpl
> > > > @@ -10,6 +10,7 @@
> > > > KERNEL_PKG_IMAGE=linux-image-${KERNEL_NAME_PROVIDED}
> > > >  KERNEL_PKG_KERN_HEADERS=linux-headers-${KERNEL_NAME_PROVIDED}
> > > >  KERNEL_PKG_LIBC_HEADERS=linux-libc-dev
> > > >  KERNEL_PKG_LIBC_HEADERS_CROSS=linux-libc-dev-${DISTRO_ARCH}-
> > > > cross
> > > > +KERNEL_PKG_KERN_CONFIG=linux-config-${KERNEL_NAME_PROVIDED}
> > > >  KERNEL_PKG_KERN_KBUILD=linux-kbuild-${KERNEL_NAME_PROVIDED}
> > > >  KERNEL_PKG_KERN_KBUILD_CROSS=${KERNEL_PKG_KERN_KBUILD}-
> > > > ${DISTRO_AR
> > > > CH}-cross
> > > >  
> > > > @@ -32,6 +33,7 @@ deb_dbg_dir=${deb_img_dir}-dbg
> > > >  deb_kern_hdr_dir=${deb_top_dir}/${KERNEL_PKG_KERN_HEADERS}
> > > >  deb_libc_hdr_dir=${deb_top_dir}/${KERNEL_PKG_LIBC_HEADERS}
> > > >  deb_libc_hdr_cross_dir=${deb_top_dir}/${KERNEL_PKG_LIBC_HEADER
> > > > S_CR
> > > > OSS}
> > > > +deb_kern_config_dir=${deb_top_dir}/${KERNEL_PKG_KERN_CONFIG}
> > > >  deb_kern_kbuild_dir=${deb_top_dir}/${KERNEL_PKG_KERN_KBUILD}
> > > >  deb_kern_kbuild_cross_dir=${deb_top_dir}/${KERNEL_PKG_KERN_KBU
> > > > ILD_
> > > > CROSS}
> > > >  
> > > > diff --git
> > > > a/meta/recipes-kernel/linux/files/debian/isar/configure.tmpl
> > > > b/meta/recipes-kernel/linux/files/debian/isar/configure.tmpl
> > > > index 389c9a85..19797b84 100644
> > > > --- a/meta/recipes-
> > > > kernel/linux/files/debian/isar/configure.tmpl
> > > > +++ b/meta/recipes-
> > > > kernel/linux/files/debian/isar/configure.tmpl
> > > > @@ -10,10 +10,20 @@ do_configure() {
> > > >      # Trace what we do here
> > > >      set -x
> > > >  
> > > > -    # Process kernel config target and fragments
> > > > -    ${MAKE} O=${KERNEL_BUILD_DIR} ${KERNEL_CONFIG_TARGET}
> > > > -    ./scripts/kconfig/merge_config.sh -O ${KERNEL_BUILD_DIR}/
> > > > \
> > > > -        ${KERNEL_BUILD_DIR}/.config ${KERNEL_CONFIG_FRAGMENTS}
> > > > +    configdir=/usr/lib/linux-config-${PV}
> > > > +    if [ -e ${configdir}/kernelconfig ]; then
> > > > +        # Prefer pregenerated kernel config
> > > > +        # So, very expensive QEMU-emulated merge_config.sh
> > > > +        # can be skipped for target specific linux-kbuild
> > > > package
> > > > +        mkdir -p ${KERNEL_BUILD_DIR}
> > > > +        cp ${configdir}/kernelconfig
> > > > ${KERNEL_BUILD_DIR}/.config
> > > > +        ${MAKE} O=${KERNEL_BUILD_DIR} olddefconfig
> > > > +    else
> > > > +        # Process kernel config target and fragments
> > > > +        ${MAKE} O=${KERNEL_BUILD_DIR} ${KERNEL_CONFIG_TARGET}
> > > > +        ./scripts/kconfig/merge_config.sh -O
> > > > ${KERNEL_BUILD_DIR}/
> > > > \
> > > > +            ${KERNEL_BUILD_DIR}/.config
> > > > ${KERNEL_CONFIG_FRAGMENTS}
> > > > +    fi
> > > >  
> > > >      # Stop tracing
> > > >      set +x
> > > > diff --git
> > > > a/meta/recipes-kernel/linux/files/debian/isar/install.tmpl
> > > > b/meta/recipes-kernel/linux/files/debian/isar/install.tmpl
> > > > index 00011517..3387671c 100644
> > > > --- a/meta/recipes-kernel/linux/files/debian/isar/install.tmpl
> > > > +++ b/meta/recipes-kernel/linux/files/debian/isar/install.tmpl
> > > > @@ -33,6 +33,13 @@ do_install() {
> > > >      # Trace what we do here
> > > >      set -x
> > > >  
> > > > +    if echo "${DEB_BUILD_PROFILES}" | grep -q "kconfig"; then
> > > > +        # Install kernel config
> > > > +        # The target specific linux-kbuild package can speedup
> > > > +        # the build using this pregenerated kernel config
> > > > +        install_kconf ${deb_kern_config_dir}
> > > > +    fi
> > > > +
> > > >      if echo "${DEB_BUILD_PROFILES}" | grep -q "kbuild"; then
> > > >          # Install kernel scripts and tools
> > > >          if echo "${DEB_BUILD_PROFILES}" | grep -q "cross";
> > > > then
> > > > @@ -223,6 +230,14 @@ install_headers() {
> > > >      kernel_headers
> > > >  }
> > > >  
> > > > +install_kconf() {
> > > > +    kernel_kconf_dir=usr/lib/linux-config-${PV}
> > > > +    destdir=${1}/${kernel_kconf_dir}
> > > > +
> > > > +    mkdir -p ${destdir}
> > > > +    cp ${O}/${KCONF} ${destdir}/kernelconfig
> > > > +}
> > > > +
> > > >  install_kbuild() {
> > > >      kernel_kbuild_dir=usr/lib/linux-kbuild-${krel}
> > > >      destdir=${1}/${kernel_kbuild_dir}
> > > > diff --git a/meta/recipes-kernel/linux/linux-custom.inc
> > > > b/meta/recipes-kernel/linux/linux-custom.inc
> > > > index 647f09dd..b21a90f3 100644
> > > > --- a/meta/recipes-kernel/linux/linux-custom.inc
> > > > +++ b/meta/recipes-kernel/linux/linux-custom.inc
> > > > @@ -25,6 +25,7 @@ KBUILD_DEPENDS ?= "build-essential:native, \
> > > >                     flex, \
> > > >                     git, \
> > > >                     kmod, \
> > > > +                   linux-config-${KERNEL_NAME_PROVIDED}
> > > > <kbuild
> > > > !kconfig>, \
> > > >                     rsync,"
> > > >  
> > > >  KERNEL_DEBIAN_DEPENDS ?= "initramfs-tools | linux-initramfs-
> > > > tool,
> > > > \
> > > > @@ -106,14 +107,14 @@ python() {
> > > >  }
> > > >  
> > > >  # Default profiles and provides
> > > > -BUILD_PROFILES = "kernel kbuild"
> > > > +BUILD_PROFILES = "kernel kconfig kbuild"
> > > >  
> > > >  # We only offer the -kbuildtarget variant when actually cross
> > > > compiling
> > > >  BBCLASSEXTEND:append:cross-profile = " kbuildtarget"
> > > >  
> > > >  # When cross-profile is active:
> > > > -# build only kernel with the default variant of the recipe
> > > > -BUILD_PROFILES:cross-profile = "kernel"
> > > > +# build only kernel and package config with the default
> > > > variant of
> > > > the recipe
> > > > +BUILD_PROFILES:cross-profile = "kernel kconfig"
> > > >  
> > > >  # -native: kbuild package for host
> > > >  BUILD_PROFILES:class-native = "kbuild"
> > > > @@ -122,14 +123,17 @@ RECIPE_PROVIDES:class-native = " \
> > > >      linux-kbuild-${KERNEL_NAME_PROVIDED}"
> > > >  # Use pseudo target to pull in the base variant of the recipe.
> > > >  # Will be auto-extended with -native by multiarch.bbclass.
> > > > -RDEPENDS:class-native += "${BPN}-pseudo"
> > > > +# Using DEPENDS, see below
> > > > +DEPENDS:class-native += "${BPN}-pseudo"
> > > >  
> > > >  # -kbuildtarget: kbuild package for target, enforcing
> > > > non-cross-build
> > > >  BUILD_PROFILES:class-kbuildtarget = "kbuild"
> > > >  RECIPE_PROVIDES:class-kbuildtarget = " \
> > > >      linux-headers-${KERNEL_NAME_PROVIDED} \
> > > >      linux-kbuild-${KERNEL_NAME_PROVIDED}"
> > > > -RDEPENDS:class-kbuildtarget = "${BPN}"
> > > > +# Using DEPENDS instead of RDEPENDS to ensure creation of
> > > > pregenerated
> > > > +# kernel config before build of target specific linux-kbuild
> > > > package
> > > > +DEPENDS:class-kbuildtarget = "${BPN}"
> > > >  ISAR_CROSS_COMPILE:class-kbuildtarget = "0"
> > > >  
> > > >  # Make bitbake know we will be producing linux-image and
> > > > linux-headers packages
> > 

-- 
Stefan Koch
Siemens AG
www.siemens.com

-- 
Stefan Koch
Siemens AG
www.siemens.com